CD40siRNA对实验性自身免疫性心肌炎大鼠Th17细胞及其细胞因子白细胞介素-17与白细胞介素-23的作用

Effect of CD40 siRNA on T helper lymphocyte-17 cells and interleukin-17, interleukin-23 in rats with experi- mental autoimmune myocarditis

目的探讨CD。小分子干扰RNA（CD40siRNA）对实验性自身免疫性心肌炎（EAM）大鼠的心肌病理改变、心肌组织中Th17细胞及外周血中IL-17、IL-23水平的影响。方法选取40只健康雄性6—8周龄Lewis大鼠，体质量185—210g，随机分为对照组、EAM组、CD。siRNA组及小分子干扰RNA（siRNA）组，每组10只。EAM组、CD40siRNA组及siRNA组以猪心肌球蛋白与完全弗氏佐剂的混合液0．2mL大鼠足垫区皮下注射，对照组大鼠足垫区皮下注射PBS0．2mL。CD40siRNA组与siRNA组免疫后第8天分别尾静脉注射CD40siRNA表达载体、siRNA表达载体。免疫后21d处死所有大鼠，光镜下观察心肌病理变化并计算心肌组织病理积分；实时荧光定量-PCR法检测心肌组织Th17细胞分化的特异性转录因子基因RORCmRNA表达水平，ELISA法检测外周血IL-17、IL-23水平。结果1．CD40siRNA组心肌组织病理积分较EAM组明显下降（2．34±0．60比3．40±0．35，P〈0，05）；2．C040siRNA组RORCmRNA较EAM组明显下降（2．13±0．28比2．93±0．36，P〈0，05）；3．CD40siRNA组IL-17水平较EAM组明显下降（114．38±8．29比148．70±5．04，P〈0，05）；4．CD40siRNA组IL-23水平较EAM组明显下降（107．00±7．69比136．98±23．16，P〈0，05）。结论CD40siRNA可减轻EAM大鼠心肌炎症，其机制可能与抑制EAM大鼠Th17细胞分化特异性转录因子基因RORCmRNA的表达、减少IL-17及IL-23的分泌有关。

Objective To investigate the effect of CD40 siRNA on the pathologic changes and T helper lympho- cyte （Th）-17 cells of myocardium and 1L-17, IL-23 of serum in rats with experimental autoimmune myocarditis（EAM）. Methods Forty 6 - 8 week old heahhy male Lewis rats with body weight of 185 - 210 g were divided into EAM group, CD40siRNA group, siRNA group, and normal control group randomly,with 10 rats in each group. The rats in EAM group, CD40 siRNA group and siRNA group were induced by immunization with cardiac C protein and completed Freund adjuvant in double foot pads. The rats in normal control group were injected with PBS buffer in double foot pads. On the 8＇h day after immunization, the rats in CD40 siRNA group were injected with C D40 siRNA expression vector, and the rats in siRNA group were injected with siRNA expression vector. The rats were sacrificed on day 21 after inoculation. The his- topathologic changes were observed by light microscope and the myocardial histopathology scores were calculated. The expression of RORC mRNA of myocardium was detected by real-time quantitative polymerase chain reaction （ RT- PCR）. Enzyme linked immunoabsorption assay was used to determine the serum level of IL-17 and IL-23. Results Compared with EAM group ,the myocardial histopathology score（ 2.34±0.60 vs 3.40 ±0.35, P 〈 0.05 ）, the expression of RORC mRNA（2.13 ± 0.28 vs 2.93± 0.36, P 〈 0.05 ） and the serum level of IL-17 （ 114.38 ± 8.29 vs 148.70±5.04, P 〈 0.05） and IL-23 （ 107.00 ±7.69 vs 136.98± 23.16, P 〈 0.05 ） were significantly lower in CD40 siRNA group. Conclusions It is suggested that CD40 siRNA expression vector might reduce myocardial injury by inhibiting Th-17 activation and down-regulating the expression of IL-17 and IL-23.